Should round duct through a block wall have a sleeve?
Raw masonry can chew into duct over time. Use an approved sleeve/trim/firestop/acoustical detail so the duct does not rub concrete and the penetration can be sealed correctly.
['Running thin duct skin directly through a rough block wall may look fine on day one, but vibration and sharp masonry edges can wear holes, damage coatings, and create leaks.', 'The recovery is to verify the wall type/rating and install a proper sleeve or protection detail before final seal/trim. The gap treatment depends on whether the wall is rated, exterior, acoustic, smoke, or ordinary partition.']
Stop if
- Use this as training guidance. The foreman, approved drawings, project specs, manufacturer installation instructions, employer safety policy, and AHJ/code requirements always control the final answer.
Check
- Unsleeved penetrations can leak, rattle, chafe holes in duct, and fail wall/firestop requirements.
Steps
- Confirm wall type: CMU, rated wall, exterior wall, shaft wall, or ordinary partition.
- Check whether duct is touching raw concrete/masonry edges.
- Verify sleeve, annular space, firestop/acoustical seal, and trim requirements.
- Inspect for vibration/contact risk and coating damage.
- Coordinate with masonry/firestop/GC before closing the wall.
More in Cutting, Holes, Penetrations & Field Fab